Dialectical Behavior Therapy (DBT) is a comprehensive psychosocial treatment that is efficacious for borderline personality disorder (BPD). In Phase I, we developed and evaluated an innovative computer-based training (CBT) prototype of a subset of DBT skills for mental health providers using an iterative process of prototype development, and tested the prototype's efficacy in a pilot randomized controlled trial (RCT). All Phase I aims were met and exceeded. In the RCT, statistically significant results favoring DBT were observed on all major outcome variables, including skills knowledge gains, ability to recall skills, as well as self-efficacy and motivation to treat BPD clients. In Phase II, we propose to expand the DBT skills CBT curricula to include two additional modules - mindfulness and emotion regulation. We will again use an iterative process of development seeking feedback from experts and end-users. We propose to conduct a RCT (N=75) comparing three groups: the DBT CBT, a comparable text-based curriculum (Guided Self-Study), and a CBT control. Major outcome variables will include DBT skills knowledge, recall, self-efficacy, motivation to treat BPD clients, as well as two clinical application measures: a performance-based assessment and a clinical application test. In addition, we propose a 3-month follow-up period to assess skills use and retention over time. [unreadable] [unreadable]